The noninflammatory, diffuse pain syndrome recognized as fibromyalgia primarily affects women between puberty and menopause. Symptoms, in addition to musculoskeletal pain and tender points, can include fatigue, nonrestorative sleep, and depression. A precipitating event such as abrupt cessation of exercise, physical injury, or prior debilitating illness can often be identified. Aerobic exercise is usually protective, but sporadic training patterns or other precipitants can place even well-trained athletes at risk. Patients need to know that they can alter the course of this syndrome. Treatment should include attempts to reverse the precipitating event, plus education, aerobic exercise, correction of any sleep disturbance, analgesia, and physical therapy.